Integrated valve design for gas chromatograph

ABSTRACT

A gas chromatograph with multiple valves is disclosed. An embodiment of the multi-valve gas chromatograph includes multiple valves and multiple thermal conductivity detectors (TCD&#39;s). This allows separation and measurement of a gas sample in one compact integrated unit.  
     Other features may also be present. For example, a first heating zone may include a band heater placed around the multi-valve block to heat the carrier gas and to keep the multi-valve block at a desired temperature. A second heating zone may include a spool and a cartridge heater to heat the columns through which the gas sample flows. Two sets of screws, one through the top of the multi-valve and one through the bottom, may be included to simplify maintenance of the multi-valve system. Insulation defining an oven can be placed around the assembly to stabilize the temperature of the multi-valve assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] This invention relates to the field of gas chromatography. Inparticular, this invention relates to a new gas chromatograph. Even moreparticularly, this invention relates to a new gas chromatograph havingmultiple valves and detectors.

[0005] 2. Description of the Related Art

[0006] The field of gas chromatography is concerned with analyzing gassamples flowing through a process pipeline. A sample is provided to agas chromatography which then separates the sample into portions anduses a variety of detectors to analyze the concentration of particularcomponents in the process stream.

[0007] Before now, a number of problems have existed with gaschromatographs. For example, fast and accurate measurements aredesirable for any gas chromatograph. A gas stream flowing through theprocess pipeline may be composed of many different classes of componentsand ideally, each of these components would be analyzed. However,conventional gas chromatographs cannot respond to process changes asquickly as desired. Futher, liquid contaminants in the process streamcan introduce further complications to any analysis.

[0008] Another problem with previous gas chromatographs is a lack offlexibility in analysis of the gas stream. It would often be desirableto analyze different characteristics of the gas stream without switchingto another gas chromatograph. However, previous gas chromatographs arerestricted because of their limited number of valves and their lack offlexibility. As such, a gas chromatograph is needed that can analyzecomplex process streams with greater accuracy and speed.

[0009] Other problems with gas chromatographs have also existed in thevalve system contained in gas chromatographs. For example, these valvesare not easy to service. Maintenance may be necessary because often theflows through a gas chromatograph are dirty, and this contamination canaffect the performance of key components in the gas chromatograph.Substitution of clean components in the gas chromatograph can minimizethe problem, but disassembling the gas chromatograph has in the pastbeen a difficult and frustrating experience. Thus, a need for a new gaschromatograph exists.

[0010] As known by those of ordinary skill, the prior art also presentsother problems that should be solved or minimized.

SUMMARY OF THE INVENTION

[0011] A disclosed embodiment of the invention is a multi-valve assemblyincluding a plurality of plates and diaphragms attached together to formmultiple valves. Each of these valves is individually actuatable by anoutside source and includes a plurality of valve ports. The assembly mayalso include a reception area where at least one fluid properlydetector, such as a TCD, may be inserted. The assembly preferablyincludes an open area in the body of plate that holds a spool. The spoolincludes a heater and heats a gas sample to a predetennined temperaturewhile the remainder of the plates heat carrier gas to a secondpredetermined temperature by use of a band heater.

[0012] The disclosed embodiment also includes two sets of screws, afirst set attaching a top plate of the invention to at least one middleplate, and a second set attaching a bottom plate of the invention to atleast one middle plate, the top plate being removable without the bottomplate becoming detached.

[0013] The invention comprises a combination of features and advantageswhich enable it to overcome various problems of prior devices. Thevarious characteristics described above, as well as other features, willbe readily apparent to those skilled in the art upon reading thefollowing detailed description of the preferred embodiments of theinvention, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more detailed description of the preferred embodiment ofthe present invention, reference will now be made to the accompanyingdrawings, wherein:

[0015]FIG. 1 is a simplified diagram of a gas chromatograph system.

[0016]FIG. 2 is a simplified schematic of a gas chromatograph.

[0017]FIG. 3A is a schematic diagram of a valve in an ON configuration.

[0018]FIG. 3B is a schematic diagram of a valve in an OFF configuration.

[0019]FIG. 3C is a schematic diagram of a multiple valve system foranalyzing a sample.

[0020]FIG. 4 is an illustrative cut-away view of a valve.

[0021]FIG. 5 is an illustrative cut-away view of a solinoid.

[0022]FIG. 6 is an exploded isometric view of an embodiment of amulti-valve block.

[0023]FIG. 7A is a top view of an upper piston plate for the multi-valveblock of FIG. 6.

[0024]FIG. 7B is a bottom view of an upper piston plate for themulti-valve block of FIG. 6.

[0025]FIG. 8A is a top view of a lower piston plate for the multi-valveblock of FIG. 6.

[0026]FIG. 8B is a bottom view of a lower piston plate for themulti-valve block of FIG. 6.

[0027]FIG. 9A is a top view of a base plate for the multi-valve block ofFIG. 6.

[0028]FIG. 9B is a bottom view of a base plate for the multi-valve blockof FIG. 6.

[0029]FIG. 10A is a top view of a primary plate for the multi-valveblock of FIG. 6.

[0030]FIG. 10B is a bottom view of a primary plate for the multi-valveblock of FIG. 6.

[0031]FIG. 11 is a sealing diaphragm for the multi-valve block of FIG.6.

[0032]FIG. 12 is a cushion diaphragm for the multi-valve block of FIG.6.

[0033]FIG. 13A is an upper actuator diaphragm for the multi-valve blockof FIG. 6.

[0034]FIG. 13B is a lower actuator diaphragm for the multi-valve blockof FIG. 6.

[0035]FIG. 14 is a cut-away view of a multi-valve assembly duringoperation.

[0036]FIG. 15 is a top view of the bottom piece of insulation for amulti-valve assembly oven.

[0037]FIG. 16 is a cross-section view of an embodiment of themulti-valve assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038]FIG. 1 shows a gas chromatograph system generally built inaccordance with the teachings herein. Gas flows through a processpipeline 1I10, a sample of which is taken by a sample probe 120 prior tobeing introduced to gas chromatograph (GC) 100. The gas sample may befiltered and heat traced generally along tubing 130 before flowing intogas chromatograph 100. This heating may be required for gases that maycondense into a part gas, part liquid flow at cooler temperatures. Afterbeing analyzed by the gas chromatograph, the gas sample is eitherreturned into the process pipeline 110, or vented to the atmosphere.

[0039] Referring to FIG. 2, gas chromatograph 100 includes valveassembly 210 connected to multiple columns 220 and detectors 230, inthis case, thermal conductivity detectors (TCD). A gas sample generallyfollows path 240 through valve assembly 210, columns 220 and TCDs 230.The valve assembly allows the selection of columns 220 which contain aliquid phase, or porous polymer, or other material that acts to separatethe gas sample into multiple portions, each portion being sequentiallyreleased to the TCDs 230. For example, a gas sample may contain variousmolecular weight hydrocarbon components. Column 220 could separate thegas sample so that lower molecular weight hydrocarbon components wouldelute from the column first, followed by a higher molecular weightcomponent, etc.

[0040] Refering to FIGS. 3A and 3B, the operation of a valve is shown.Valve 300 includes a plurality of valve ports, labeled 1-6. It will beappreciated that more or fewer number of ports may also be used.Incoming line 310 provides a gas sample to valve 300. Exhaust line 320expels the gas sample from the valve 300. Solid lines 330 show openpassages between ports, whereas dotted lines 340 indicate blockedpassages between the ports.

[0041] A solenoid (not shown) places valve 300 into either an ONposition, as shown in FIG. 3A, or an OFF position, as shown in FIG. 3B.When a valve is in the ON position, gas flows from incoming line 310,through port 1 to port 6, through line 315 and finally through port 3 toport 2 and out exhaust line 320. Wien the valve is in the OFF position,gas flows from incoming line 310, through port 1 to port 2 and outthrough exhaust line 320.

[0042]FIGS. 3C and 3D illustrate how a pair of valves may operate eitheralone or in combination with additional valves (not shown). A firstvalve 300 includes ai array of 6 valve ports. A second valve 350 alsoincludes an array of6 valve ports. Associated tubing 310, 315, 320, 325and 390, and columns 360 and 370 are also shown as well as dual TCD 380.

[0043] Incoming line 310 is attached to a sample transport line (notshown). When first valve 300 in an OFF position, gas sample flows fromincoming line 310 to port 1 to port 2 of the valve 300 and out exhaustline 320. When valve 300 is in an ON position, however, gas sample flowsfrom port 1 to port 6 and then through sample loop 315. That gas thenflows from port 3 to port 2 of valve 300 and is expelled out exhaustline 320. At this time, the sample loop 315 is filled with a gas sample.This means that, if valve 300 is turned OFF at this time, a gas sampleis trapped within the sample loop 315.

[0044] Turning now to valve 350, when it is in an OFF configuration,carrier gas flows from carrier gas input line 390 through port 2 ofvalve 350, to port 1 and then through carrier tubing 325. At this time,valve 300 is also in an OFF configuration, so that the carrier gas intubing 325 is forced through port 5 to port 6 and through gas sampletubing 315. Consequently, this action forces the (gas sample down column360 via ports 3 and 4. The gas sample can then additionally be forcedthrough column 370 and into the dual TCD 380 via ports 4 and 3. Manyother port combinations also exist and are within the skill of one inthe art. Thus, the valves may be connected in series to form “channels.”

[0045] Each channel feeds into a corresponding TCD pair (a measurementTCD and a reference TCD). Use of more than one TCD pair results in asimultaneous analysis by the TCD's of the sample flowing through theircorresponding attached columns. This parallel analysis results in aincreased analysis speed as compared to serial analysis. Further.because tecluology currently limits the channels and the detector pairsto a one-to-one correspondence, the number of chanmels in use at anyparticular time is limited both by the number of valves and by thenumber of detectors. Of course, the greater the number of valves, thegreater the number of potential channels, and the more potential formore parallel processing and a faster overall system. But even if thenumber of detectors limits the number of channels being used at any onetime, a greater number of valves results in a greater number of channelsfrom which to choose for each TCD. For example, a multi-valve system mayhave sufficient valves to operate eight channels. Even if only twodetector pairs exist, such that only two channels can be in use at anyone time, the detector pairs can be designed to select which chaimelamong those eight channels it is conmected to. This dramaticallyincreases the flexibility of the presently disclosed gas chromatographsystem.

[0046] Referring to FIG. 4, a cross-section of a partial valve assemblyis shown. Valve 400 includes a base plate 410 with activation ports 412and 414, a lower actuator diaphragm 420, a lower piston plate 430 withassociated long piston 435, upper actuator diaphragm 440, upper pistonplate 450 with associated short piston 455, cushion diaphragm 460,sealing diaphragm 465, and primary plate 470 with valve ports 472 and474 therein. These valve ports suitably could be ports 1 and 6 as shownin FIG. 3.

[0047] Referring back to FIG. 4, gas sample 480 enters valve port 472.This gas sample 480 travels out valve port 474 when long piston 435 isin an elevated (closed) position and short piston 455 is not. Longpiston 435 is elevated by gas pressure applied to activation port A 412.This pressure deforms lower actuator diaphragm 420 and forces longpiston 435 in an upward direction in lower piston plate 430. Upper endof long piston 435 then abuts against primary plate 470. Similarly,short piston 455 is actuated by gas pressure from activation port B414,and forces gas sample 480 to path 485.

[0048] Whether a valve is in an ON or OFF position depends upon asolenoid that applied gas pressure alternately to either activation portA or activation port B. FIG. 5 generally illustrates the operation of asolenoid. Solenoid 500 includes a common line port 510, exit port 520corresponding to activation port A, exit port 530 corresponding toactivation port B, release port 525 for exit port A exit port B, andcontrol leads 540. Tubing 550 connects to each of common line port 510,and exit ports 520 and 530. Exit ports A and B connect to activationports A and B in FIG. 4, respectively. Common line port 510 conmects toa gas under pressure. Gas pressure applied to either of activation portA or activation port B controls whether the corresponding valve is in anON or OFF position. Electrical control signals from leads 540 controlwhether common line 510 is connected to exit port A or exit port B, andthus whether gas pressure is applied to activation port A or activationport B. Some variation to the particulars of this design is possiblewhile still staying within the teachings of the invention.

[0049]FIG. 6 shows an exploded view of an embodiment of the multi-valveblock 600 including an open area 605, base plate 610 with associateddowel pins to align components, a lower activator diaphragm 620, a lowerpiston plate 630 with associated long pistons 635, an upper activatordiaphragm 640, an upper piston plate 650 with associated short pistons655, a cushion diaphragm 660, a sealing diaphragm 665, and a primaryplate 670. Each piston includes a lower base portion with a poleextending therefrom. Hole sets 680 and 690 are suitable for two pairs ofTCD's. First set of screws 615 for insertion through base plate 610,lower piston plate, and upper piston plate are shown as well as a secondset of screws 675 for insertion through primary plate 670, upper pistonplate 650, lower piston plate 630, and base plate 610. In addition,because there are five valves, five solenoids (not shown) are alsopresent, each controlling a different valve.

[0050] As can be seen, the multi-valve device 600 includes 5 valves,with each valve having six ports. By integrating multiple valves into asingle multi-valve block, a compact device is achieved that can separatea gas sample into a large number of columns as discussed above. Thisfacilitates faster and more precise analysis of the gases contained inthe gas sample. Manufacturing costs can also be reduced. The teachingsherein can be used to integrate more or fewer than 5 valves into asingle unit, and more or fewer valve ports per valve. For example, if agreater number of valves is desired, up to 7 valves can easily belocated in the embodiment shown in FIG. 6.

[0051] One manner in which the embodiment of FIG. 6 makes faster andmore precise analysis of the gas sample is reduction of what is known as“dead volume.” Increased dead volume results when the components of agas chromatograph are widely spaced and undue mixing of the fluidoccurs. This mixing of the gas or fluid sample results in a “bandbroadening.” Band broadening is undesirable because the area of eachband of an analysis corresponds to a concentration measurement and thesebands should not overlap. Consequently, a series of broad bands resultsin a much slower analysis than is possible with a series of short bands.Therefore, an integrated, compact design is particularly desirable froma performance perspective. Further, the illustrated geometry providessufficient area for a first and second set of TCD's. While these TCD'smay be located outside the multi-valve block if desired (e.g. tointegrate a greater number of valves into the multi-valve block), theinclusion of the TCD's in the multi-valve block helps furtherminiaturize the device and make it more compact.

[0052]FIGS. 7A and 7B show top and bottom views respectively of theupper piston plate of FIG. 6. Refeiring to the top view of FIG. 7A,locations 701-705 for 5 valves are shown. Screw holes, generally at 720,are also shown for accepting screws to tighten together the primaryplate with other plates. Holes 750 are for screws from the bottom, totighten the plates together, while holes 760 are for dowel pins toposition the valves. Tuniing to the bottom view of the upper pistonplate shown in FIG. 7B, locations 701-707 are similarly shown. Eachvalve includes sufficient room 730. 735 for 3 piston bases and 3 pistonpoles. Raised edges 740 around the perimeter of each valve location arealso shown. The raised surfaces defined by the raised edges exist onboth sides of the upper and lower piston plates. A raised edge of 0.032inches could be used, for example. These raised edges 740 reduce thesurface area upon which the screws 615 and 675 provide force and therebyreduce the chance of leakage.

[0053] Referring back to FIG. 6, it can be seen that two sets of screwsare shown corresponding to holes 720 and 750. These two sets of screwsthat protrude tlirough holes 720 and 750 simplify maintenance of theinvention. A bottom set of screws 615 extends tirough the base plate610, lower piston plate 630, and upper piston plate 650. Screws 615attach these plates together. A top set of screws 675 extends throughthe primary plate, the upper piston plate, and the base plate to holdthose plates together. This dual screw set approach simplifiesmaintenance because the loosening and removal of screws 675 allowsaccess and replacement of the sealing diaplragm 665 and cushiondiapliragm 660 without disassembly of a greater number of plates thannecessary. It is the sealing diapliragm that becomes most contaminatedby the dirty gas that flows through the multi-valve. A relatively lowtorque of about 10 ft/lbs. has been found acceptable for these screwsets while making the removal of these screws as easy as possible. Themulti-valve configuration also simplifies maintenance because, by virtueof multiple valves in an integrated unit, replacement of only onediaplragm is necessary rather than the multiple diaphragms that wouldothervise be necessary for multiple valves.

[0054]FIGS. 8A and 8B show the lower piston plate of FIG. 6. FIGS. 8Aand 8B are the upper and lower views respectively of the lower pistonplate. Referring to FIG. 8A, once again, locations 801-805 are providedfor the five valves, in addition to an area for two sets of TCDs. Holes820 and holes 825 accept tightening screws. Also shown are fivetriangular grooves 830 and accompanying holes 840 within each groove.Gas from the solenoids travels tlrough the actuation holes 840 to thegrooves 830. These grooves 830 provide a path for the actuation gas thatelevates the short pistons. Because the valves of the illustratedembodiment have six ports, and thus three short pistons per valve, atriangular shape is convenient (but not necessary) to actuate all threeshort pistons simultaneously. Turning now to the bottom view of FIG. 8B,locations 801-807 are shown. Also generally shown at 840 are holesconnected to an actuator port through which gas exerts pressure. Theseholes 840 correspond to the grooves 830 of FIG. 8A. As can be seen,space 830 is provided for the base of long pistons 635.

[0055]FIGS. 9A and 9B show the top and bottom views respectively of thebase plate. Referring to FIG. 9A, similar to FIG. 8A, a plurality ofgrooves 930 are shown, with each groove encompassing a hole 940 foractuator gas. In addition actuator holes 945 traveling up to the lowerpiston plate are additionally shown. FIG. 9B illustrates the bottom viewof the base plate. Illustrated are slot 960 and holes 970, 980, and 990.Slot 960 is present because it simplifies the removal of plates upondisassembly. In particular, after a valve has been assembled, thediaphragms tend to stick to a contact surface, and the slots provide anarea where the plates can be easily grabbed onto. Hole 970 is a port Aand B common line that coinects to port A and B on solenoids via tubing.Holes 980 and 990 are screw holes. FIG. 9B also shows cross-drill lines962 and 964 representing drilled areas for insertion of carrier andsample gas tubing. Holes at the entrance to each insertion area are alsoshown. The carrier and sample gas are quickly and reliably preheated inthe insertion areas defined by cross-drill lines 962 and 964 from thewarmth in the multi-valve block.

[0056]FIGS. 10A and 10B show the upper and lower view of a primary plateof FIG. 6. Referring now to FIG. 10A shown are TCD holes 1050-1053 andassociated tubing holes 1060-1063. Also shown is a hole 1070 suitablefor a RTD heat sensor. FIG. 10B shows a bottom view of the primaryplate. Included are holes 1010 to accept screws and 1020 to accept dowelpins.

[0057] FIGS. 11-13 illustrate the diaphragms of FIG. 6. FIG. 11 showsthe sealing diaphragm of FIG. 6. The sealing diaphragm is preferablymade from 2 mil thick Kapton™ made by DuPont with a 0.5 mil tefloncoating on each side. FIG. 12 shows the cushion diaphragm of FIG. 6. Thecushion diaphragm is preferably about 0.002″ thick and is made fromNomax paper by DuPont. FIGS. 13A and 13B illustrate upper and loweractuator diaphragms. Both actuator diaphragms are preferably made from 3mil thick Kapton™ made by DuPont.

[0058]FIG. 14 illustrates a multi-valve block 1400 including a spool1410 with areas for a first RTD (Resistance Thermal Detector) 1420 andtwo TCD pairs 1425, an exterior surface 1430 to the multi-valve block1400, a band heater 1440 outside of the exterior surface 1430, carriergas preheat tubing 1450 located between the exterior surface 1430 andthe band heater 1450, and a base plate 610 as part of the multi-valveblock. Spool 1410 contains one or more cartridge heaters 1460 and asecond RTD 1465. Referring back to FIG. 6, a hole or open area 605 ispresent in the middle of the multi-valve block. The open area 605accommodates spool 1410 that protrudes fiom the base plate 610. Columns1470 wraps around the spool 1410. Also shownt are solinoids 1480connected via tubing 1485 to the base plate at its lower end 1490. Bandheater 1440 is an AC band heater of approximately 200 Watts power.

[0059] During operation, a gas sample flows through tubing or conduits315 (not shown in FIG. 14) in the multi-valve block prior to flowingthrough the piping of the columns 1470. In contrast, the carrier gasflows through the carrier gas preheat tubing 1450 prior to flowingthrough columns 1470. The carrier gas preheat tubing may be located atdifferent positions to heat the carrier gas to a predeterminedtemperature. The carrier gas preheat tubing may be just inside the bandheater as shown in FIG. 14, or it may preferably occupy insertion areasin the multi-valvc block, as explained in reference to FIG. 9. Thus,prior to being warmed by the spool, both the carrier gas and the assample are heated to approximately the temperature of the multi-valveblock.

[0060] Thus, this arrangement provides for two heating zones. The areaproximate to the spool 1410 defines a second heating zone. A firstheating zone is defined by the temperature of the remainder of themulti-valve block. The first RTD located in the multi-valve block at1420 measures the temperature of the first heating zone. The second RTDlocated at 1465 within the spool 1410 measures the temperature of thesecond heating zone. Two separate heating zones are important becausethe gas flowing through the columns 1470 should ideally be about 3-5° C.higher than the temperature at each TCD (the temperature of the firstheating zone). In addition, the TCD's in the first heating zone shouldbe kept to within about 0.1° C. of a predetermined temperature foraccurate analysis. The temperature variation in the second heating zoneshould also be maintained within about a 0.1° C. tolerance. More heatingzones may be added when desired to allow the analysis of the complexsamples.

[0061] In order to stabilize the temperatures in heating zones, an“oven” is created from a thermal insulation material. This oven isessentially a cylindrical sleeve that surrounds the rest of themulti-valve device and keeps its temperature stable, except for thesolinoids, which must be kept away from the heat inside the oven.Referring to FIG. 15, an illustrative bottom 1500 of this insulationcylinder or sleeve is shown. As can be seen, it contains a number ofholes 1510, through which extend the tubing for the solinoids and thelegs of the base stand.

[0062]FIG. 16 illustrates the insulation 1610 for the “coven” includingthe bottom 1500 of the insulation cylinder. As part of them multi-valveblock 1400, base plate 610 is adjacent to the bottom of the insulationcylinder 1500. Legs 1600 to create stand-off are made from Teflon™ 1605.Also shown is tubing 1485 that extends through the bottom piece 1500 tothe lower surface 1490 of the multi-valve block 1400.

[0063] While preferred embodiments of this invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit or teaching of this invention. Theembodiments described herein are exemplary only and are not limiting.Many variations and modifications of the system and apparatus arepossible and are within the scope of the invention. Accordingly, thescope of protection is not limited to the embodiments described herein,but is only limited by the claims that follow, the scope of which shallinclude all equivalents of the subject matter of the claims.

What is claimed is:
 1. A multi-valve assembly, comprising: a unit including a plurality of plates and diaphragms attached together to form multiple valves, each of said valves being individually actuatable and having a plurality of valve ports.
 2. The multi-valve assembly of claim 1, wherein said unit forms a reception area for at least one fluid property detector.
 3. The multi-valve assembly of claim 2, wherein said fluid property detector is a thermal conductivity detector.
 4. The multi-valve assembly of claim 1, wherein a number of said plates have a ring shape forming an open area in the body of each of said number of plates.
 5. The multi-valve assembly of claim 4, wherein said integrated unit further includes a spool occupying a portion of said open area, said plates defining at least a first heating zone and said spool defining at least a second heating zone.
 6. The multi-valve assembly of claim 5, wherein each of said first and said second heating zones include at least one temperature detector and wherein said first heating zone is maintained about a first predetenrined temperature and said second heating zone is maintaned at about a second predetermined temperature.
 7. The multi-valve of claim 5, wherein said first heating zone is maintained by a band heater located approximately concentrically around at least one of said plates and said second heating zone is maintained by a second heater in said spool.
 8. The multi-valve assembly of claim 5, wherein gas sample tubing and carrier gas tubing( attach to said valve ports, at least a portion of said gas sample tubing being inside said second heating zone and at least a portion of said carrier gas tubing being in said first heating zone.
 9. The multi-valve assembly of claim 1, further comprising a plurality of actuator ports in at least one of said plates, each of said valves corresponding to a pair of actuator ports.
 10. The multi-valve assembly of claim 9, further comprising a plurality of solenoids, each of said solenoids being attached to one of said pairs of actuator ports via tubing, each of said solenoids capable of actuating a corresponding one of said valves.
 11. The multi-valve assembly of claim
 2. further comprising: a plurality of fluid property detectors located in said reception area; a temperature detector proximate to at least one of said fluid property detectors.
 12. The multi-valve assembly of claim 1, further comprising: an insulative housing surrounding said plurality of plates.
 13. The multi-valve assembly of claim 1, further comprising a first set of screws and a second set of screws, wherein said multi-valve assembly includes at least three plates, said plates being in a generally stacked arrangement, wherein a first of said plates is a top plate, a second of said plates is a bottom plate and a third of said plates is a middle plate, said first set of screws being inserted through said top plate, said second set of screws begin inserted through said bottom plate, wherein said at least three plates are attached together, said top plate being detachable from said middle plate upon removal of said first set of screws from said top plate while said middle plate and said lower plate remain attached while said second set of screws remain inserted through said bottom plate.
 14. The multi-valve assembly of claim 1, wherein each valve corresponds to ane area on said plurality of plates, at least one of said plurality of plates including an elevated surface at each of said areas.
 15. The multi-valve assembly of claim 1, further comprising: a set of a plurality of pistons corresponding to each valve, said each of sets of pistons having first and second subsets wherein each valve is in either an ON condition or an OFF condition, with said first subset being, actuated when each valve is in an ON condition and with said second subset being actuated when each valve is in an OFF condition.
 16. A multi-valve device comprising: an integrated block having multiple valves and multiple detectors, each of said valves being suitable to direct selectively a fluid flow and each of said detectors positioned to analyze at least a portion of said fluid flow.
 17. The multi-valve device of claim 16, further comprising: a plurality of fluid sample detectors at least partially within said integrated block.
 18. The multi-valve device of claim 16,wherein said multi-valve device defines first and second heating zones, said second heating zone being, concentrically surrounded by said first heating, zone.
 19. The multi-valve device of claim 18, wherein a gas sample is heated in said second heating, zone and a carrier gas is heated in said first heating zone.
 20. The multi-valve device of claim 16, further comprising: a first set and a second set of screws tightened paitially through said multi-valve device, said multi-valve device being, conifigured to paitially disassemble upon removal of said first set of screws. 